This invention relates generally to infusion therapy and IV injection or sampling sites, and more particularly to an injection or sampling site, such as an IV injection site, adapted for use with a blunt cannula.
In an effort to reduce the risk of transmitting infectious diseases, such as hepatitis and AIDS, via accidental needle sticks, various designs of IV injection sites have been developed that are adapted to receive a blunt cannula and/or shielded cannula. See, e.g., Special Report and Product Review, Needlestick-Prevention Devices, Health Devices, pages 154-180 (ECRI, Plymouth Meeting, Pa. 1991). One approach has been to employ a slit septum Y-site in which a slit elastomeric septum is compressed in the Y-site housing. A blunt cannula can be introduced through the slit of the septum, and assuming the design works as intended, the septum will seal against the cannula shaft. When the cannula is removed, the septum seals itself.
Injection sites of this type are either available from or publicized by Baxter International, Inc., Deerfield, Ill., under the trade designation "Baxter's Needle-Less Injection Sites"; Abbott Laboratories, Inc., Abbott Park, Ill., under the trade designation "LifeShield Infection Control System"; and Kendall McGaw Laboratories, Inc., Irvine, Calif., under the trade designation "SafeLine No-Needle I.V. System". A blunt cannula has been available from Becton, Dickinson and Company, Paramus, N.J., under the trade designation "Interlink System".
In many of these systems the slitting of the septum is critical to their proper functioning. The slit in the septum is created in a secondary operation after the molding of the septum is complete. The slitting of the septum often requires precise accuracy in the location of the slit. Moreover, custom-made tools, secondary operations and subsequent testing are often required to form acceptable leak-resistant slits.
The injection or sampling site of the present invention provides a reliable, leak-resistant site for the introduction of blunt cannula. The injection or sampling site is easier to make and less expensive than previously available injection or sample sites because the slit can be formed in the septum at the time the septum is made, rather than in a separate step after the septum is made. This eliminates the difficulties in accurately cutting the slit in the septum, and the creation of particulate matter resulting from such cutting operations. This further eliminates the need for the special tooling, and the resulting tooling maintenance, to form the slit in the septum in a separate manufacturing step.
The injection or sampling site of the present invention is adapted to receive a blunt cannula. Generally, the injection or sampling site comprises a housing having an outside end and a passageway extending inwardly from the outside end, the passageway defining an axial direction, and an elastomeric septum closely received in the passageway of the housing, the septum having inside and outside ends relative to the outside end of the housing. There is a slit extending through the septum generally in the axial direction. The slit is formed by a hole through the septum that is flattened against itself to seal against itself when the septum is assembled in the housing. The passageway of the housing includes a septum-receiving portion, and one of the septum-receiving portion and the septum has a generally elliptical cross section to preferentially compress the hole in the direction between either the corresponding shorter dimension of the elliptical septum-receiving portion or the corresponding longer dimension of the elliptical septum.
In one embodiment of the injection or sampling site, the septum has a generally elliptical cross-section having longer and shorter dimensions, and the housing is generally cylindrical, so that the hole through the septum is preferentially compressed in the direction along the longer dimension of the septum. The hole in the septum can have a circular cross-section before installation in the housing, but the hole preferably has a generally elliptical cross-section, with the longer dimension of the elliptical bore being aligned with the shorter dimension of the generally elliptical septum and the shorter dimension of the bore being aligned with the longer dimension of the generally elliptical septum.
In another embodiment of the injection or sampling site, the septum has a generally circular cross-section, and the housing has a generally elliptical cross-section having longer and shorter dimensions, so that the hole through the septum is preferentially compressed along the direction of the shorter dimension of the housing.
Thus, the injection or sampling device of the present invention provides a site for the introduction of a blunt cannula. The site is of simple construction, and can be made with a septum having a hole preformed therein, eliminating the need for a separate slit-forming step, and the attendant problems of properly locating the slit, and providing the specialized tooling to properly form the slit. The injection or sampling site is thus faster and easier to manufacture than prior designs, and should result in cost savings and quality improvements.
These and other features and advantages of the invention will be in part apparent and in part pointed out hereinafter.